Olfactory Predator Discrimination in Yellow-Bellied Marmots

Many mammals discriminate the scents of their predators (reviewed in Apfelbach et al. 2005) and this trait may be heritable (there is genetic variation in the degree of response to synthetic fox [Vulpes vulpes] odor in rats [Rattus norvegicus], Rosen et al. 2006). The mechanism underlying this identification may be relatively experience-independent, or it may rely on specific experience with predators. The distinction is important for both theoretical reasons—we should know how much experience is required for the proper performance of important behaviors (Curio 1993; Caro 2005; Reznikova 2007), as well as for practical reasons—when species ranges change, prey may suddenly encounter new predators and their fate may rest on whether or not they can respond to these novel predators (e.g., Berger et al. 2001; Blumstein 2002). A mechanism by which prey might identify novel predators relies on the inevitable creation of sulfurous metabolites that are then excreted in the urine or feces of carnivorous mammals (Nolte et al. 1994). If prey species are sensitive to the odor of these substances, then predator-experienced prey should respond to any predator scent. This expectation is supported by observations that North American beaver (Castor canadensis), black-tailed deer (Odocoileus hemionus), alpine goats (Capra hircus), and European rabbits (Oryctolagus cuniculus) respond to the scent of African lion (Panthera leo), with which they have had no experience on ecological or evolutionary Correspondence Daniel T. Blumstein, Department of Ecology and Evolutionary Biology, University of California, 621 Young Drive South, Los Angeles, CA 90095-1606, USA. E-mail: [email protected]